Control for charging storage batteries.



F. W. SCHMIDT.

GONTROL FOB. CHARGING STORAGE BATTERIES.

APPLICATION FILED MAY 4, 1910.

Patented Nov. 22, 1910.

@illllllllllll MHERQQEYW' fu-v'" WITNESSES rem-acumen u. ecntnrn'r, or retrrlenurlrnm, PENNSYLVANIA.

COl'i'lIiEt-OL FOR CHARGING STORAGE BATTERIES.

Specification of Letters Patent.

Patented Nov. 22, 1910.

Application filed May 4, 1910. Serial No. 559,286.

-vice for cutting out charging circuit" in charging store "e batteries at the rise of temperuture in the some beyond a predetcr' n'zined point.

further consists of en improved ther mostct such controlling device.

further of other novel features cou:- tioi'u nll us be hereinafter Eng my invenlowiu u r accompanying oc form thereof which is at pres erred by me, since the same has in practice to give satisfactory and reliable results, although it is to be understood that the various instrumcntulities oi which my invention consists cun be variously urrunged and organized and that my invention 4 not limited to the precise an rzijngemcut but-i sire to moire. such changes ads Will come wiiiiin the scope of my invention.

Figure tive view of 2 represents pic v of t e same. Fig. 3 repr nts u llongn. dinui section of the thermo Fig i; represents a top plan View of the sumo with the cover removed. Fig. 5 is s c'1gmmn'uriicul representation of u cl'mrgim circuit, it storage battery and an automatic cutout to which thethermostut is upplicitl.

Similar numerals of reference indicate corresponding parts in the figures.

Reforming to the drawings: The present invention is an imprm'ement upon the invention dis used in my ctr-pending uppli- (iattflOil, Serial No. 537,803, filed Jan. 13, 1910, buttery temperature controller. Said lat static device immmfscd in :1 storage battery during charging of the some and constructed to actuate u cutout device-in the charging circuit to cut out the battery when the telnperuture in the smnerisesbeyond a predetermiued'point. This thermostat has a me- (1 organization of these instrumcntuhtres as herein shown and described 12, is secured to ,1 consists essentially in a thermo- In the diagram, Fig. 5, the battery to be charged is indicated by the numeral 1, having one conductor, 2, leading through switch 3, from one terminal oii a generator, 4, and another conductor, 5, connected to the other terminal of the generator. This comprises the charging circuit. 'An automatic circuit breaker, in the present instance disclosed as a knife-switch, 6, is connected in the circuit and-closes the same. when the blade of the switch engages its terminals and is so held by a trigger which forms ,a part of or is connected to the armature of an electro-magnet, these parts forming at holding and releasing device, 7, for the cirwit-breaker. The electro-magnet is Wound in a branch or shunt circuit, one terminal, 8, of which is connected to the charging circuit through the circuit breaker, While its other terminal, 9, is connected to one contact member of the thermostat- 10, which is immersed in the buttery solution, when the device is in operation. All of these elements and connections are substantially the some us those disclosed in my above referred to application, and need not be specifically described.

The thermostat has a casing, 11, of lead or other acid-resisting metal, and a plate, the bottom of this casing and in electric Contact with the same. A composite strip, 13, such as usually employed in thermostats, is secured to this plate and will contact, ivhen flexed by rise of temperature, with u contact-screw, 14, in an arm 15, secured upon but insulated from a screw-post, 16, upon the base 12. The contact-screw is connected Wire, 17, to a screw, 18, which is insulated from the cover of the casin by means of an insulating Washer, 19, and projects outword through an opening in the cover. The enlarged base, 20, of a. screw-post, 21, of lead or similar acid-resistin metal is secured upon the screw, and is insulated from the cover by an insulating filling, 22, also closing the opening in the cover. The screwpost 21 has a transverse hole, 23, through Wnich the wire terminal of the branch or shunt circuitcan be inserted and secured by a nut, 24, preferably of hard rubber or other acid-resisting and non-conducting material. The casing is tightly closed by its cover which is soldered 0r fused on, and its interior is completely filled with a heatconducting but insulating liquid, such as transiormer oil or similar oil, which will maintain insulation of the parts Within the casing, conduct heat from the Walls of the c sing to the thermostat strip, and prevent the formation of an are between the contact points and thus preserve the same from burning or fusing. The casing fits within an aperturcd insulating jacket, 25, of hard rubber or other insulating material, which will prevent metallic contact of the casing with the battery elements and atthe same time give free conductive access for the S0lution to the surface 01" the casing. The apertures 26 of the jacket will permit the solution to act against all sides of the casing to convey a part of the battery-current to the same, metallic contact of the casing with the elements of the battery and thus prevent short circuiting by accidental contact of the easing with two elements.

When charging a battery, the terminals of the charging circuit, which has been closed at the main switch 3 and circuitbreaker, are connected to the binding posts or similar terminals of thebattery, and the the battery. The thermostat, which is connected to one terminal of the shunt circuit, is placed in the battery, immersed in the solution. If, during the charging of the battery, the temperature in the latter rises above a predetermined degree,-usually about 105 Fahrenheit,-to which the thermostat has been adjusted to close contact, the contacts close the shunt-circuit through the same, as the casing of the thermostat forms a terminal in the battery and thus diverts a portion of the circuit flowing but the jacket will prevent direct l I l l l t l l l l l I l terminal of the through the battery, to the shunt circuit. This Will energize the electro-magnet 1n the shunt-circuitand cause the latter to attract its armature and release the circuit-breaker which will thus cut out the battery from the charging circuit and prevent damage from overheating and overcharging. All of this operation is substantially or my other'application, above referred to, excepting in so far as the thermostat casing, or as much thereof as is metallic, is therein disclosed as in contact with a battery element, While in the present device, the shunt circuitderives its connection in the battery circuit by the thermostat casing forming a terminal of the shunt circuit in the battery without direct contact, in tact, being insulated from such contact-by its jacket, but deriving its current when the contact of the thermostat is closed through the battery solution which carries the current.

like in the device tery solution, and this provision is furnished.-

by inclosing ,the casing in its insulating jacket, and making the thermostat casing a shunt circuit in the battery, active only when the contacts Within it close by rise of temperature. At other times, of current from the generator Will thus charge '1 course. the casing is inert.

Having thus described my 1nvent1on,what I claim as new and desire to secure by Letters Patent, is:

FREDERICK W. SCHMIDT.

lVitnesses:

G. D. MCVAY, M. E, RINKENBACH. 

